Here's the question you clicked on:
dietrich_harmon
Prove using coordinate geometry: If a point is on the perpendicular bisector of a segment, then it is equidistant from the endpoints of the segment.
|dw:1359842711196:dw| choose the perpendicular bisector to be the \(y\)-axis, and the length of the segment \(2a\), so that \(Q(-a,0)\) and \(R(a,0)\) compute \(\overline{PQ}\) and \(\overline{PR}\)